Brakes: S60 binding rear brakes

[runner-up]

The rear brakes of my 2003 S60 D5 tend to bind. The problem occurs when it first goes over about 60mph and then gets worse. Eventually the rhythmic knocking disappears after two or three miles at motorway speed, but recurs after the brakes are used again.

If I stop the car and get out whilst the problem's there, the offending rear brake gives off a great deal of heat, therefore I believe the knocking is caused by binding brakes. It can affect one side or both sides.

It's happened every few months for the last couple of years, and can be temporarily solved by pushing the caliper pistons back and exercising them in and out once or twice, besides cleaning the sliders and lubricating them with copper grease. The car is fine for about 3 months, then one or both of the rear brakes start binding again. I'm careful to allow fluid to be expelled by loosening the bleeder, so as to avoid putting back pressure on the master cylinder or ABS seals.

The car's done 160,000 miles, but actually covers a very low mileage most weeks. Sometimes it doesn't go above 40mph for a month or so. Nevertheless, the calipers shouldn't normally seize up after such a short time.

I've replaced the rear discs and pads in case one of the discs was warped, but that didn't make any difference.

My suspicions is that I need to replace the calipers, although there's no guarantee that used ones would be any better, and I'm reluctant to pay for a pair of new or recon units on a car of this age.

If the problem is with the ABS unit then this wouldn't solve the problem anyway.

No faults have shown on the fascia warning screen.

Anyone have any suggestions?

[Longhouse21]

You could try striping and cleaning the Copperslip from the slide pins and other areas and change to Ceratec, HT silicon grease or rubber grease. There is a perception in some circles that Copperslip is the wrong thing to use and can "harden" in time causing the pins to slide less effectively.
I'd also look at the pad slide area as dust and corrosion can build up there causing the pads to move less freely. If that's the case, a good clean up with a wire brush and maybe a light dressing with a file is in order before applying a touch of one of the lubes mentioned above.

edit: Some have re-built the calipers with new seals when they have been problematic. I had a sticking caliper (NSR - which seems to be the most common one from the information I've found) but decided a replacement was the way to go. PFS http://www.partsforvolvosonline.com/...p?cPath=52_512 as they were an outright purchase, no exchange, and cheaper than ECP, Volvo & others who were providing a recon exchange unit?

[barrybritcher]

copper grease will clog up and is only really for the back of the pad.

anything inside a boot (slide pins etc) use silicone grease

[barrybritcher]

http://www.carlube.co.uk/greases/car...purpose-grease

[CLIVERALLY]

Or red rubber grease.

[Georgeandkira]

Your description sounds amiss and oddly obfuscative.

You get a rhythmic knocking some of the time...you say you exercise the caliper and apply MORE copper grease...then you tap off brake fluid (?).
You replaced the pads and rotors. Did you inspect (or take notice) of the handbrakes' lining condition? Did you take notice of the condition of the glide pins?

Where is it you're reapplying copper-slip exactly? Sounds 'funny'.

Did you or friends do these tasks? How may cooks are spoiling this broth?

Copper slip is not the stuff to use there.

I suggest you tear it all down and clean the $#!T out of and off of everything.
Roll the hub with your hands to be sure you don't have two bad bearings. At 160,000 this could easily be the case.
Even bad bearings will withstand your prolonged low speed operation. "Sometimes it doesn't go above 40mph for a month or so" is the queerest quote of the year!

Get real brake part grease as mentioned above and reassemble. Using copper-slip or anti-seize on brake parts is downright Edwardian.

Is the parking brake hardware intact and all present? Inspect the operation of the handbrake cables too.

If you (and possibly your mates) aren't sure what you're doing it would pay to have it sorted.

[barrybritcher]

Originally Posted by Georgeandkira

Your description sounds amiss and oddly obfuscative.

You get a rhythmic knocking some of the time...you say you exercise the caliper and apply MORE copper grease...then you tap off brake fluid (?).
You replaced the pads and rotors. Did you inspect (or take notice) of the handbrakes' lining condition? Did you take notice of the condition of the glide pins?

Where is it you're reapplying copper-slip exactly? Sounds 'funny'.

Did you or friends do these tasks? How may cooks are spoiling this broth?

Copper slip is not the stuff to use there.

I suggest you tear it all down and clean the $#!T out of and off of everything.
Roll the hub with your hands to be sure you don't have two bad bearings. At 160,000 this could easily be the case.
Even bad bearings will withstand your prolonged low speed operation. "Sometimes it doesn't go above 40mph for a month or so" is the queerest quote of the year!

Get real brake part grease as mentioned above and reassemble. Using copper-slip or anti-seize on brake parts is downright Edwardian.

Is the parking brake hardware intact and all present? Inspect the operation of the handbrake cables too.

If you (and possibly your mates) aren't sure what you're doing it would pay to have it sorted.

He is saying when he pushes the piston back in, before putting the caliper back on - he is cracking the bleed nipple to avoid flipping the seals... not rocket science

[barrybritcher]

I agree with Clive, clean, check, re apply proper stuff AND check the bearing AND handbrake shoes.

[Dancake]

If the slider pins are free, then the problem could lie with the caliper piston seals, the caliper piston, the pad/caliper carrier or the brake hoses. If you're reluctant to buy refurbed calipers for a car of that age, then at what age would you have been tempted to buy them? Maybe at 8 years old? Would you be upset at having to replace parts on a car at 5 years old? Perhaps you would because you'd be convinced the parts should last longer? You admit the fault has been there for a couple of years, so even at 11 years old you felt the car was too old to consider replacing safety critical parts? At what point do you draw the line? Not quite sure I follow your logic.

[runner-up]

Thanks for the advice chaps - I'll buy a pair of calipers from the suggested supplier. They are nowhere near as dear as I expected; in fact I paid more than that for a caliper for an Austin Metro in 1987. And I'll try one of the other lubricants suggested to go around the pad lugs.

At least nobody suggests an ABS fault, so I'm optimistic that the cost of new calipers should be money well spent.